Improvement of Combustion and Exhaust Emissions of Used Vegetable Oil in Marine Diesel Engine

Abstract

 In this research, used vegetable oil without esterification was used in a medium speed marine diesel engine as an alternative fuel. The effects of fuel properties, such as kinematic viscosity, evaporation characteristics, ignition delay, and fuel injection control, such as fuel injection pressure and fuel injection pattern (pre-injection and after-injection) on the combustion characteristics and the exhaust emissions were investigated using a test bench. Results show that: the evaporation characteristics and ignition delay of the fuel have much effect on combustion characteristics and the exhaust emissions, but kinematic viscosity has hardly any effect; the fuel injection control such as pre-injection with little injection quantity is effective in reducing smoke, CO, unburned HC and PM at low load operation.